@Skry: you have brought up several interesting points. From my point of view, our most scarce resource is manpower, so I would focus on what we don't have at first, instead of improving what we already have in less-than-ideal form.

So:
* I would go with the mer kernel
* I would stay with some available and maintained base (arch linux or debian or mer comes to mind)
* and put some effort in the wayland/e17 stuff as we currently lack a good graphical touchscreen-enabled environment.